Printing



J. GROAK 2,616,961

PRINTING Nov. 4, 1952 Filed Nov. 26, 1947 4 Sheets-Sheet 2 11v VFN To 4 Jun- Gf AK Nov. 4, 1952 J. GROAK 2,616,961

PRINTING Filed Nov. 26, 1947 4 Sheets-Sheet 5 i uw zjvrwe: Joszr 60AK Patented Nov. 4, 1952 PRINTING Josef Groak, London, England Application November 26, 1947,'Serial No. 788,301 In Great Britain September '23, 1946 Section 1, Public Law 690, August .8, 1948 Patent expires September :23, 1966 26 Claims. (01. 17s 5..2.)

This invention relates to improvements in and relating to printing and consists in a new method of producing latent or visible images of all kinds such as monochromatic or heterochromatic reproductions of objects, i. e. symbols, scenes, inscriptions and other representations of all kinds, or theproduction of graphic representations of oscillatory phenomena such for example as oscillograms, cardiograms or radar indications.

It is an object of the invention to enable such monochromatic or heterochromatic productions or reproductions to be made by a transference method, rapidly and at low cost even in circumstances where only one or only a small number of the productions or reproductions are required.

A further object of the invention is a method enabling such productions or reproductions to be made in the form of positive or negative reliefs and coloured if desired.

The method according to the present invention for making latent or visible images, consists in bringing into contact with one another two surfaces, one of which contains, consists of or is coated with a substance or composition adapted to be softened by heat, and scanning the surface of said substance or composition with a controlled beam of radiant or corpuscular energy to soften parts thereof so thatmaterial is transferred from one surface to the other surface in correspondence with said softened parts of the substance or composition on the one surface when the two surfaces are in contact.

In the production of representations or images of oscillatory or other phenomena such as can be expressed in the formof electricalsignals, such signals are utilised to modulate the beam of radiant or corpuscular energy scanning the surface of the heat-softenable substance or composition.

In the making of reproductions of objects, symbols, scenes, inscriptions and other representations of all kinds, the method according to the invention includes the preliminary step of scanning the representations to be reproduced, thereby producing electrical picture signals and utilising the produced picture signals to modulate the beam of radiant or corpuscular energy scanning the surface of the heat-softenable substance or composition.

Again, a reproduction may be made utilising a patterned mask or stencil between a scanning beam of radiant or corpuscular energy and the surface of the heat-softena'ble substance or composition. In some cases also, a patterned mask may be used in conjunction with a scanning beam modulated for producing other effects as outlined above and the patterned mask may in such case be disposed on eitherside of the surfaceof heat-softenable composition or substance.

The material transferred may be the heatsoftened substance or composition itself orit may be a material present on the other surface and which is transferred by being taken up by the softened parts of the heat-softenable substance ortclzfmposi-tion when brought into contact there- Wl In some cases the transfer may be a partial transfer, the transferred substance adhering to the receiving surface without leaving the original carrying.surface,so that parts of the two surfaces are caused to adhere. In such-case the adhering parts, or, using a transparent or translucent transferable substance, the parts of the original carrying surface corresponding thereto, constitute the required production or reproduction and the strip or other body on which the production or reproduction is to be viewed is transparent or translucent so that the production or reproduction may be viewed through the transparent or translucent strip or body. This arrangement may be such that theadhering surfaces may be parted from one another after use and the strips or other bodies bearing the surfaces used again in making other productions or reproductions.

,It will readily be understood that the images may be produced either on the surface of the receiving material or body, i. e. that not originally bearing the 'heat-softenable substance or composition, as a result of its reception of the elemental softened parts of the substance or composition from the other surface, or on that other surface i. e. the surface originally containing, consisting of or coated with the heat-softenable material, as the result of abstraction of elemental parts of the substance or composition therefrom.

The scanning of the surface of the heat-softenable substance or composition may take place whilst it is in contact with the other surface or alternatively it may take place a short time before the two surfaces come into contact with one another.

The images produced by the methods forming the subject of the present invention may be monochromatic or heterochromatic and heterochromatic reproductions may be made conforming closely to the natural colours of coloured objects, scenes or representations to be reproduced.

The modulated beam may be conveniently the electronic beam of a cathode ray tube modulated by signals derived from object-scanning means of any known kind such as an iconoscope. Alternatively a concentrated beam of infra-red radiation may be utilised in conjunction with for example a movable concave reflector or mirror, or a lens transparent to the radiation, the scanning movements of the beam to influence the transferable material being controlled in accordance with signals derived from the iconoscope or other objectscannmg means.

In the production of a monochromatic reproduction of a black and white or coloured object by the method according to the invention, a material may be used containing, consisting of, or coated with a substance adapted to be rendered transferable Lmder the influence of a modulated scanning electron beam and having combined for transfer therewith, either one or more black or coloured substances, or one or more substances adapted to be selectively coloured by further specific substances subsequently applied thereto.

In a method for the production of a heterochromatic reproduction of a coloured object by electronic means in accordance with the invention a series of areas of transferable compositions of different colours corresponding to the component colours of the required reproduction are employed, and the object to be reproduced is scanned through a similar series of separate colour filters each of which is of a colour complementary to the pigmentary colour of one of the transferable compositions, the signals produced by the object-scanning means at each scan through one colour filter being inverted and thereafter utilised to modulate an electron beam scanning an area of transferable composition of thecolour which is complementary to that of the said one colour filter, the scanned areas of different colour being brought in succession, after scanning by the modulated electron beam, into contact with the same area of the material or body on which the heterochromatic reproduction is to be made. The modulating signals may be produced with a single iconoscope or other object-scanning means making a series of scans in succession each through a different colour filter or a series of separate iconoscopes each scanning through-e, different colour filter may be used.

A heterochrom-atic reproduction can be built up using three or more component colours and a further colour, such for example as dark grey, or black, may be added to the heterochromatic reproduction, for example for the purpose of modifying or correcting the colours applied previously, by transferring elemental parts of said further colour in the manner previously described, but in most cases without the interposition of a colour filter between the object and the scanning device.

The compositions, adapted to be rendered transferable under the influence of a modulated radiant energy or corpuscular beam, and suitable for use in carrying out the present invention, include substances which are capable of being softened at least once by the application of heat and which are capable of being retained by the surfaces of bodies or materials to which they are applied in their softened state.

These compositions may be inherently coloured by the incorporation therein of one or more coloured substances, such as dyestuffs or pigments or mixtures thereof, or the compositions may include one or more substances which can be selectively coloured by treatment subsequent to the step of transferring, or which will 4 act as selective mordants for dyes subsequently applied thereto.

Alternatively, transferable compositions may be employed which are capable of producing an etch-ground or resist so that printing plates, stencils, masks, meshes and patterns may be produced.

The following three examples are given of compositions which are suitable for use in carrying out the present invention.

Parts by weight Crestavin resin 282 (a modified cresylic resin) 75 Paraffin wax, high melting point (about 63 C.) 10 Petroleum jelly 15 Ester gum Palm wax 15 Paraffin wax, low melting point 5 Laculose B (an esterified gum) Petroleum jelly 15 The above compositions may be suitably coloured by incorporating therein, one or more pigments and/or dyestuffs the exact amounts of such pigments and/or dyestuffs added depending on their particular colour strengths, or covering powers, and the following are given as typical examples.

Parts by weight Uncoloured composition (e. g. A, B or C) 75-85 Pigment 25-15 Uncoloured composition (e. g. A, B or C)- -95 Dyestuif 10- 5 Uncoloured composition (e. g. A, B or C) 70-83 Pigment 2545 Dyestufi 5- 2 The dyes used in the above examples are, of course, of such a kind as are soluble in the compositions.

Transferable compositions may also be used containing a substance having thermo-setting properties but which is incorporated in the transfer composition in a physical or chemical state such that it is capable of being softened at least once by the application of heat, though usually such ther-mc-sensitive compositions can be heat-softened several times before finally setting to an infusible condition and this facilitates the use of the compositions. Suitable compositions of this kind are solutions of a ureaformaldehyde resin, in a solvent and containing a pigment or dyestuif and compositions in this form are suitable for ready application to a carrier strip, of paper for example.

In addition to, or instead of, colouring matter such as pigments or dyestuffs, the compositions may contain one or more heat-sensitive chemical compounds, such as silver stearate or lead-thiobenzoate, which change their colour permanently under the influence of heat, with the result that the colour of the elemental parts of the composition, which are rendered transferable under the influence of the heat generated by the modulated beam of radiant or corpuscular energy, is changed either simultaneously with the composition being rendered transferable, or afterwards by subsequent heat treatment.

Apparatus for making reproductions by methods in accordance with the invention are illustrated in the accompanying drawings, in which:

Figure 1 is a part sectional view in elevation showing the layout of an apparatus suitable for use in making reproductions of an object in black and white or in monochrome,

Figure 2 is a further view of a part of Figure 1 on an enlarged scale,

Figure 3 is a part sectional view in elevation showing the layout of an apparatus suitable for use in making heterochromatic reproductions of a coloured object,

Figure 4. is an enlarged perspective view illustrating one arrangement for bringing the transferable composition and the material on which the reproduction is to be produced into close contact,

Figure 5 illustrates a modification whereby reproductions may be produced on both sides of a single strip of material simultaneously,

Figure 6 illustrates, diagrammatically, a further apparatus for the production of images by the method according to the invention.

Figures 1 and 2 show apparatus for carrying out the production continuously, of reproductions of an object, in black and white or in monochrome, on the surface of strip material such, for example, as paper.

The apparatus here shown comprises an exposure unit and a printing unit and in Fgiure l the exposure unit is shown as a television pickup tube I I, with associated electrical equipment I2 and I2, I8 represents the power source common to the exposure and printing units, and the remainder of the figure constitutes the printing unit.

The scanning device or pick-up tube II is conveniently an iconoscope and its associated time base circuits I2 and I2 are of a kind such that the rate of scanning of the iconoscope mosaic is usually slower than in television practice. In other respects however the iconoscope operates in known manner to scan the whole area of an image of the object, formed on its mosaic by any suitable known optical system (not shown) to produce picture signals.

The printing unit comprises a cathode ray tube I3 having a glass or non-magnetic metal envelope open at the end remote from the electrodes I4 and deflector plates I5 and sealed into the wall of a chamber I3 adapted to be highly evacuated through a tube I'I leading to an exhaust pump (not shown); and the construction of the chamber I6 is such that a strip of material bearing the heat-softenable, and in this case transferable, substance or composition and a strip of material on which the reproduction is to be made can be introduced into, and removed from, its interior, and in the case illustrated, in such a manner that the vacuum within the chamber I3 is not destroyed. Whilst the iconoscope or other pick-up tube I I as stated above is associated with two time bases I2 and I2 for line-scanning and frame-scanning respectively, the cathode ray tube I3 is associated with a line-scan time base 23 only. Time base is connected through a synchronising circuit 2I, with the line-scan time base I2 of the iconoscope I I so that the electron beam, represented by line 22 in Figures 1 and 2 may be caused to linescan only, in synchronism with the line-scanning 6. of the object by the iconoscope II. Frame-scanning in the operation of reproduction is achieved in this case by moving the strips within the chamber I6, past the electron beam in a direction transverse of the line-scanning plane of the electron beam and at a speed related to the speed of frame-scanning of the object by the iconoscope II.

The cathode ray tube I3 is shown in greater detail in Figure 2, 23 being the cathode maintained at the required potential from the power source I8, and indirectly heated by means of a filament 24 connected with the power source I8, and 25 is the grid interposed between the cathode 23 and an electro-magnetic focusing coil 26, fed from the power source I8, for focusing the electron beam 22. Suitable bias is applied to the grid 25 from the power source I8. I9 is an amplifier for applying amplified picture signals, generated by the iconoscope I I, to the grid 25.

The internal surface of the cathode ray tube I3 is coated with an electrically conductive material such as that known under the trade name aquadag to form an anode 21, insulated from the envelope of the tube I3 when the latter is of metal, and this anode is electrically connected with the power source I8.

The means whereby the strips are introduced into, and removed from, the chamber I6 and moved past the cathode ray tube I3 whilst in said chamber are as follows:

The chamber I6 is formed at its lower end with two wells 28 and 29 containing mercury or another appropriate liquid into which project bafiles 33, 3| disposed so that an inner part I6 of the chamber, which contains the cathode ray tube I3, is isolated from two outer parts I6" and I6' of the chamber I6 by liquid seals.

The outer I6 and IG' of the chamber I6 are connected with an exhaust pump (not shown) by Way of tubes 32 and 33 so that a pressure is maintained therein, which, though higher than that in the highly evacuated part I6, is lower than atmospheric.

By this arrangement the pressure diflerence between the part I6 and the parts I6 and "5" of the chamber I6 is kept small, with consequent limitation of the height of the mercury column required in the liquid seals. The strip bearing the transfer material is shown at 34, being in the form of an endless band supported by a series of guide rollers 35, 3B, 31, 38, 39, 40, 4|, 42, 43, 44 so as to travel between chamber parts I3 and I6" and traverse the liquid seal in well 28. The rollers 38, 42 and 43, immersed in the mercury, are preferably hollow and apertured to permit entry of mercury to overcome buoyancy.

The lower part of chamber part I6 forms a reservoir for transfer composition 45, the composition being supplied, usually in a hardened or set condition, from a hopper 46 to a cylinder 41, in which it is warmed by heating means of any known kind such as a steam pipe coil 48, and thereby liquefied or softened to such an extent as to enable it to be transferred to chamber part I6 by a pump 49. In some cases a pump may be unnecessary, the sub-pressure in chamber part I5 being sufficient to draw in the softened composition.

A transfer roller 50 is mounted for rotation partly immersed in the body of liquid or softened composition 45 and in contact with a part of the band 34 engaged by the roller 35, so that composition is transferred to the band 34 to form a coating, the thickness of which is regulated by a doctor blade i. The applied coating on band 34 hardens to a condition in which it is not transferable until again subjected to heating.

The transfer roller 50 within chamber part I6 is driven by an electric motor 52 at a given speed, through a suitable form of electro-magnetic coupling (not shown), or alternatively a driving motor may be disposed within the chamber part I5", and the roller 35 supporting a part of the band 54 is driven at a corresponding speed to move the coated band 34 in the direction of the arrows in Figure 1 through the liquid seal into and out of the highly evacuated chamber part I6. The speed of the driving motor, and therefore the rate of movement of the band 5 is controlled from the frame-scan time base I2 of the iconoscope through a synchronising circuit 53, the arrangement being such that the band is moved at a speed corresponding or related to the frame-scanning speed of the iconoscope I I.

The paper or other strip material on which the reproduction is to be made is indicated at 54. The strip 5d is taken from an external supply reel 55 through the subatmospheric chamber part Ifi' through the liquid seal in well 29, into the highly evacuated chamber part it, out from the latter again through the liquid seal into the subatmospheric chamber part IIi' and is finally caused to emerge from the latter to be received upon a suitable drum 55 for example, being guided in these movements by a series of rollers 51, 58, 59, 65, El, 62, 53, 6d, 55 and E5.

Sealing means are provided at the point of entry and exit of the strip 55 to and from chamber part I6 and this may be a liquid seal similar to those previously described, or alternatively mechanical sealing means may be provided as shown consisting of a large diameter soft roller 6?, of rubber for example, and a pair of smaller diameter soft rollers 68 and 69 adapted to make pressure contact with the entering and emerging runs of the strip 54 passing between them. The rollers El, 58 and 69 are mounted so as to fill, and make yielding pressure contact with the boundary of the aperture in the wall of the chamber part '6!!! The strip 55 is moved in the direction of the arrows in Figure l, at the same speed as the coated strip 34, being drawn through the apparatus by engagement with a pulley ii! driven at appropriate speed by the same motor 52 driving the coated strip 35.

The two guide rollers 45 and (ii within the highly evacuated chamber part It are arranged, as shown in Figures 1 and 2, to bring the coated side of the moving coated strip 35 and the strip 54 on which the reproduction is to be made, into rolling pressure contact with one another and the position of these rollers 45 and ti is such that the electron beam from the tube focused by the focusing coil 26 impinges upon the coated surface of strip 34 at points on a line immediately preceding, but as close as possible to, the pinch between the two rollers 45 and 5! carrying the two strips 313 and 54.

The electron beam spot, which represents the finite dimensions of the electron beam at the focal point on the transferable coating, moves to and fro or scans on lines transverse to the direction of movement of the coated strip 35 and the coating composition is rendered transferable quantitatively in accordance with the instantaneous variations in the beam intensity and the heat generated thereby, which in turn are inversely proportional to the point to point variations in light and shade or colour tone of the object to be reproduced, so as to be transferred to the strip 54 at the adjacent line of pressure application, and the rate of movement of the strips 34 and 54 being suitably related to the frame-scanning speed of the iconoscope II, the composition transferred to the strip 54 forms the required reproduction.

The roller 40 supporting the part of the coated strip being scanned is preferably an electrically conducting roller electrically connected with the anode of the cathode ray tube I3 or otherwise maintained at a suitable potential with respect to the cathode 23 of the tube I3, and such a roller may be a rubber covered metal roller or a roller formed of or including rubber and having for example graphite dispersed in the rubber.

The amount of transferable composition which is softened at any given point on the coated band 34 by the electron beam 22, for subsequent transference to strip 54, is determined by the instantaneous value of the electron beam current so that resulting transfer from that point will be a reproduction of a corresponding element of the picture or object as seen by the iconoscope I I and the integrated result of the transference of successive elemental parts of the composition to strip 54 will be a positive reproduction thereon of the picture or object in black and white or monochrome.

The reproduction will be a positive or negative reproduction according to the nature of the iconoscope or other object-scanning device and the total number of stages of amplification employed. When the object-scanning device is of a kind which would produce a negative reproduction, and a positive reproduction is required, the picture signals generated by the scanning device, and used for modulating the electron beam, in addition to be amplified in the amplifier l9, may be inverted with the aid of any known form of electrical inversion means, before being applied to the grid 25 of the tube l3.

The apparatus described above is intended for use in the making of reproductions continuously on a moving strip, but the invention is, of course, applicable to the making of one or a succession of pictures on a strip or body which remains stationary together with the strip the surface of which bears the composition to be transferred during periods in which the modulated electron beam, both line-scans and frame-scans an area of the composition, in synchronism with the linescanning and frame-scanning of the object-scanning device.

With the size of the spot kept constant, temperature rise of the transferable coating on the band 34 is dependent upon the beam current and the rate of line-scanning of the electron beam, the latter as previously stated may, if necessary, be made slow compared with the linescanning speeds used in television practice.

Normally the line-scanning speed is kept constant and the required spot temperature obtained by adjustment of the beam current, though it is to be understood that temperature adjustment may be effected by change of scanning speed or by combined adjustment of beam current and scanning speed. Adjustment of the unmodulated beam current at the commencement of operations is usually made to give a spot temperature approximately equal to the softening temperature of the transferable composition.

In the alternative arrangement as shown in Figure 4 a composition coated band 34 and an uncoated strip 54 are brought together over a common roller H with the coating composition between the band and strip and in contact with the latter. The electron beam 22 of the cathode ray tube 13 is focused on to the surface of the strip 54 and line-scans as before in the direction of the axis of the roller H, the roller H being rotated and the band 34 and strip 55 being moved past the beam at a speed corresponding to the frame-scan speed of the iconoscope H.

The composition is softened as before, with resultant transfer from the band 34 to strip The reproduction is formed either on the strip 54 by the composition transferred thereto, or on the band 34 by the extraction of composition therefrom, or on both simultaneously.

In Figure is illustrated a part of a further form of the apparatus employing two bands 36 coated with transferable composition moving around two guide rollers s9 and making contact with the two opposite faces of a strip 54 passing between the two rollers 49. Two electron beams 22, from two cathode ray tubes, modulated either by the output picture signals from a single iconoscope H, or modulated respectively by the output picture signals from two separate iconoscopes ll, scan the coated surfaces of the respective bands 34 on lines close to the pinch between the rollers 46, so that reproductions of the same, or different objects as the case may be, may be produced on opposite sides of the strip 4.

Using an apparatus of this kind and a trans parent strip 55, two coloured component reproductions of the same object may be formed in register with one another on the two sides of the strip using two iconoscopes and further coloured component reproductions may be superimposed on the first by subjecting the same areas f strip to further subsequent scans by the modulated electron beams to produce, say four colour combination reproductions.

To produce the individual coloured component reproductions, the object or scene is scanned by an iconoscope through a colour filter to generate picture signals, the produced signals being inverted electrically and utilised to modulate the electron beam scanning the transferable composition. The transferable composition is in this case of a colour complementary to that of the colour filter used.

Heterochromatic reproductions of an object may be made, using apparatus of the same gen eral kind as previously described for use in pro ducing in monochrome or black white, by employing appropriate colour filters interposed in succession between the objects and the scanning iconoscope, or by illuminating the object with specific colour radiations succession, the colours of which are the same as those passed by equivalent colour fiiters, and utilising the respective sets of picture signals to modulate the beams scanning the surface of coated hands brought in succession into registering contact with the material on which the reproduction is to be made.

Three-colour or other heterochromatic positive reproductions of an object can be made continuously by the method according to the present invention.

The method of colour reproduction according to the present invention makes use of analysis of. the radiation from an illuminated object into radiation of the three spectral colours, orange, green and violet, which are used, one at a time in succession, in a manner yet to be described, to control the transference of compositions of pigmentary colours complementary to those of the three spectral colours, respectively, with the result that transferred elements of the compositions of different colour co-operate to form the heterochromatic reproduction, which, through subtractive colour blending, is in the substantially correct natural colours against the correct background.

The use of a given colour filter in conjunction with a composition whose pigmentary colour is the complement of that of the filter, is to render correctly a white or gray background in the reproduction. A coloured object alone (i. e. without background) can be reproduced correctly by making use of a colour filter in conjunction with a composition of the same colour (since there are no intermediate negatives to be produced as in normal printing practice) however, a coloured object against a white background would appear in the reproduction as a coloured object against a dark background, it this direct method is used. If a white or grey background is required therefore, it is necessary to use filters and compositions which are complementary one to another in conjunction with electrical inversion of the iconoscope scanning signals. By inversion is understood electrical inversion in which a strong signal is weakened and a weak signal is correspondingly strengthened, and this may be accomplished using known inverter circuits. This artificial inversion may be regarded as analogous to the inversion which takes place during the formation of positives from negatives in known colour printing practice.

Apparatus for carrying out the method of three-colour reproduction in accordance with the present invention is illustrated in Figure 3 of the accompanying drawing: in this figure those parts of the electrical equipment unnecessary to an understanding of the further description have been omitted.

In the figure three cathode ray tubes l3, of a form similar to that described with reference to Figures 1 and 2, are mounted in spaced relationship within a closed casing constituting a chamber [8, including a chamber part It containing the tubes l3 and adapted to be highly evacuated by way of a tube I1 and an exhaust pump (not shown), and chamber parts I6 and IS isolated from the chamber part I6 by mercury or other liquid seals 28 and 29, similar to those previously described, chamber parts I6 and IB being in communication with an exhaust pump (not shown) by way of tubes 32. and 33 whereby a sub-atmospheric pressure may be maintained therein.

The chamber part IE5" encloses three separate composition reservoirs 65, similar to the reservoir 45 of Figure 1, and each supplied separately with transferable coating composition from a separate hopper 46, heated cylinders 41, 48 and pump 49. For convenience of illustration one hopper, cylinder and pump combination only is shown in the drawing. The transferable compositions are of difierent colour in each reservoir 15, being respectively blue, red and yellow.

Three endless bands 34, 34 and 34" are mounted on guide rollers as clearly shown, to travel each between one of the reservoirs 45 and the interior of the highly evacuated chamber part i8 and each band is coated, in its respective reservoir 45, with a layer of transferable composition of one of the three colours by contact with transfer rollers 50 in the manner fully described with reference to Figure l. The endless bands 34, 34' and 34" all enter and leave the highly evacuated chamber part I6 by way of the mercury seal 28.

The thickness of the coatings on the bands is controlled with the aid of doctor blades i.

All three bands 34, 34' and 34" are driven at similar and constant speed and in the same direction as shown by the arrows from a common motor 52 through a gear box I4, chains I2 and I3, and suitable magnetic couplings enabling band supporting rollers 35 within the reservoirs to be driven from the exterior of the chamber part I6", and the transfer rollers 56 for the coating composition may be driven by belts I5 from the rollers 35.

Within the chamber part I6 are mounted three main and separate guide rollers 46 for the bands 34, 34 and 34", these rollers being of relatively large diameter and each corresponding to the roller 40 of Figure 1, and being mounted equally spaced from one another. The remaining bandsupporting rollers are idler rollers, some of which may be adjustable, to guide the bands under suitable tension, between their respective coating pick-up rollers 35 in chamber part I6 and exposure rollers 40 in chamber part IS.

The single strip of material on which the reproductions are to be produced is shown at 54. It is taken from a supply reel 55 led round a series of guide rollers, first into chamber part I 6", thence through the liquid seal 29 into the highly evacuated chamber part I6, then out through the liquid seal 29 into chamber part I6', finally emerging from the latter and engaging with a pulley I0 also driven from the gear box 14, whereby the strip 54 is drawn through the apparatus. Entry and exit of the strip 54 to and from the chamber part I 6" takes place through a mechanical sealing device formed, as previously described, by three rollers 61, 68 and 69, of soft rubber making yielding pressure contact with the ingoing and outgoing runs of the strip 54 and with the boundaries of the aperture in the wall of the chamber part I 6" so that sub-atmospheric pressure may be maintained in chamber part I6'.

Within the highly evacuated chamber part I6 are provided three sets of rollers, each comprising three rollers 66, 6|, 62, the intermediate roller SI of each set being arranged close to one of the guide rollers 40 of the coated bands 34, 34 and 34".

The strip 54 is caused to pass around these rollers in the course of its travel in the chamber part I6 in such a manner that the strip is brought into yielding pressure contact with each of the bands 34", 34' and 34 in succession at the points where the latter are in contact with the rollers 40.

The three cathode ray tubes 13 are mounted in the chamber part I6 so that the electron beam of each can be focused on the coated surface of a different one of the three bands at points just preceding the pinch between a roller 46 supporting a band and its related roller GI supporting the paper or other strip material.

The exposure unit comprises three iconoscopes II, II and II", electrically connected through amplifier and inverter circuits (not shown) each with the grid of one of the cathode ray tubes I3 in such a manner that the picture signals generated by each iconoscope are utilised, after inversion and amplification, to modulate the electron beam of one tube I3. Three colour filters, I6, 11 and i8, which are orange, green and violet respectively, are placed between the three iconoscopes II, II and II" and the object 19, in such a manner that an orange image is thrown onto the mosaic of the iconoscope II, a green image onto the mosaic of iconoscope II and a violet image onto the mosaic of iconoscope I I When these coloured component images are scanned in the several iconoscopes, picture signals appropriate thereto are generated at each, and the signals from each are passed to the appropriate one of the tubes I3 associated with the bands 34, 34 and 34", bearing the related coating composition of complementary pigmentary colour, to modulate the beam thereof.

With this apparatus, three colour reproductions of an object or scene can be produced continuously on the surface of strip material, such as 54, and in the following manner:

The strip material 54 is drawn continuously into the chamber part IB', through the mechanical seal 68, 63, thence through the liquid seal 29 into chamber part I 6' at a constant speed related to that of frame-scanning in the iconoscopes II, II and II". Within chamber part I6 it traverses all three rollers 6| in succession and afterwards emerges from the chamber part I6 through the same liquid seal 29, through the chamber part I6' and finally through the mechanical seal 6?, 68, to engage with the driving pulley ID. The bands 34, 34 and 34", each with an applied uniform coating of one of the three different compositions in hardened condition on its surface, are passed from sub-atmospheric chamber part It into chamber part It through the liquid seal 28 and back again, the speed of travel being the same speed as that of the strip material 54.

The bands 35, 34 and 34" for supplying the transfer composition may conveniently have an intaglio relief pattern, which divides the surface of the bands into a plurality of very small individual cells or depressions. This relief pattern may be produced by preliminarily etching a flexible metal or etchable band or by moulding a flexible plastic band.

The doctor blades 5|, are in such a case, arranged to scrape the surface of the pre-formed bands, usually with an oscillatory movement so as to leave composition only in the individual cells or depressions. In this way the composition is divided into a multiplicity of very small parts each isolated from the others, with the result that any tendency for spreading of the heat generated on the composition during scanning thereof is eliminated or reduced and good definition in the final reproduction ensured.

The iconoscopes II, II and II, the mosaics of which bear orange, green and violet images of the object 79 respectively, generate picture signals and the set of signals of each one iconoscope is utilised, after amplification and inversion, to modulate the electron beam of one of the cathode ray tubes I3. The modulated electron beams of the tubes l3 are arranged to line-scan the composition bearing surfaces of the bands 34, 34 and 34 respectively on lines just preceding the lines of pressure contact between the bands and the strip material between the pairs of rollers 40 and 6|.

The heat generated by the modulated electron beam spots as they scan across the composition-coated faces of the respective bands, cause the successive softening of elemental parts of the compositions and these are transferred onto the strip-material 54, as the bands and strip-material come into pressure contact with one;- another: The results of. the. softening." and' subsequent transference of all the: elemental. parts, the amounts of; which. are proportional to the light and; shade ofthe corresponding picture elements of the component images formed on the. mosaics of the iconoscopes H, H and H, aretheformation of three component reproductionsof the object: on the strip-material 54' in yellow, red and blue, respectively.

The. guide rollers'for'the' bands 34., 34" and 34" or for the. strip 54, or for both the bands and the strip, are adjusted so that each red component reproduction is transferred in. exact register with the yellow component reproduction. previously formed, andeach blue component reproduction is transferred in exact register with the combined yellow and red component reproductions previously formed. The three component reproductions combine to. form. a heterochromatic reproduction'of the coloured, object, 18. It will be understood that at the commencement of operations several yellow component reproductions be produced before the first of such yellow component reproductions reaches the position in which a red component reproduction is formed inregister with it. This is, however, no disadvantage when the continuous production of a number of colour reproductions of a single stationary object or scene-is contemplated.

One or more further colours, or black, may be applied to correct or modify the three-colour reproduction produced by the method last described, by providing further printing units in conjunction with the appropriate iconoscopes, colour filters and inverter circuits.

It will be appreciated that in the continuous processes described above, strips or webs. precoated with the: appropriate composition may be used in place of the bands 34 inwhich case: the arrangement described above forthe: continuous application. of a coating of heat-softenable com position to the bands 34- is'unnecessary.

The production. of a single or a small number of heterochromatic. reproductions of a stationary coloured object may'also be carried out by op erating the iconoscopes one after the other, the separate. sets of picture signals generated by the iconoscopes being utilized to modulate the. re-

spective electron beams of the cathode ray tubes l3, to which they are separately connected, in timed relationship with. one another such that the yellow, red and blue component reproductions: are produced in. correct register on the strip. In other words, the picture signals from the iconoscope |l-",. operating with the violet filter 18, are generated and utilised directly in the production of the yellow component reproduction and the picture signals from the corresponding iconoscopes H and H are generated and utilised respectively in the production of the red and blue component reproductions only when the already made yellow component reproduction and the combined yellow and red component reproductions have respectively reached their correctpcsitions in the printing unit.

An example of a further apparatus specially suitable where. the making of: single or small numbers of monochromaticor; heterochromatic productions or reproductions is required; utilising the method according to the invention, is illustrated in Figure 6 of the accompanying drawings.

In Figure 6-,. the evacuated chamber isrepresented by [6 as in the-previously described. con-.-

structi'on', said chamber [6 containing the. oathode ray tube I3. The band carrying the heatsoftenable. composition is shown at BI], and in this case the band is carried by two spools 8| and 82 in such a manner as to be capable of being moved in either direction through the chamber [6 by winding off one spool and onto the other, suitable driving means (not shown) for the spools, such as an electro-magnetic coupling, being provided to enable them to be driven in one. direction or the other from the exterior of the chamber IS.

The band is pre-coated with three heatsoftenable compositions of the. colours yellow, red and blue which have appreciably different softening temperatures. Thev difierent compositions cover separate areas of the band and are applied so as to form a sequence of successive areas with the colours succeeding one another in the required order.

Reproduction is made upon sheets of paper introduced into the chamber It by means of a carrier belt 83 extending between the outside of the chamber 15, through a liquid seal 84, and if necessary a mechanical seal of the kind previously described, into the interior of the chamber, being guided by a series of rollers, including two main positioning rollers 85.

The inner end of the carrier belt 83. is connected with a spring-driven roller 86 the arrangement being such that the belt 83 together with the paper sheets may be drawn into the chamber by the roller 86 to bring a paper sheet to a position where it is stretched between the positioning rollers and approximately at right angles to the electron beam 22 in the manner shown.

The coated band 38 is caused to make surface contact with the paper sheet between rollers 85 by means of a pair of guide rollers 81 which are carried in bearings at the lower ends of rods 88 adapted to be raised and lowered by solenoids 89.

In operation, with the guide rollers 81 raised to permit the coated band 80 to take the position away from the carrier belt 83, the belt 83 is moved to bring a paper sheet, carried thereby, into the position where it extends between positioning rollers 81. The coated band 80 is moved to bring an area of yellow coloured composition opposite the paper sheet and the solenoids 89 are operated to lower the rollers 81, thereby bringing the yellow coloured composition into contact with. the paper sheet. With the paper sheet and the coated band stationary, the heat-softenable composition is line and framescanned by the electron beam 22 modulated by the amplified and inverted picture signals generated by the iconoscope which has scanned the object through a violet colour filter so that a yellow component reproducion is formed on the paper sheet.

The rollers 8! are retracted and the band 8!! moved to bring an area of red composition opposite the paper sheet which has remained stationary and after bringing the red composition into contact with the paper sheet, scanning is repeated, the modulating picture signals being derived from an object scan by the same iconoscope but through a green filter.

The abovedescribed steps are again carried out to bring a fresh area of composition into contact with the paper sheet and scanning again carried out, the modulating picture signals being those derived from an object scan by the iconoscope through an orange filter; The three component reproductions are made in register with one another.

It will be understood that in the example the heat-softenable coating is scanned by the modulated electron beam through the body of the band 80.

The coloured compositions of different colour are selected so that the softening temperatures thereof are different and so that a temperature suificient to soften the blue composition is in sumcient to soften the already transferred red and yellow compositions, and similarly a temperature sufficient to soften the red composition is insufiicient to soften the already applied yellow composition.

The spot temperature of the unmodulated scanning beam 22 is adjusted between scans to correspond with the softening temperature of the next coloured composition to be scanned.

In cases Where the Width of the strip of material on which the production or reproduction is to be made is so large as to make the use of one electron beam impossible or undesirable, several electron beams, modulated by the signals generated as a result of scanning a'corresponding number of contiguous areas (considered transversely) of an object, by one or several scanning devices, are utilised to enable the full width of the strip to be covered, each of the several electron beams being arranged to scan a part of the sists for half-tone plates may be formed or alternatively the required tone effects of a production or reproduction may be achieved directly by utilising such a screen and forming half-tone productions or reproductions.

In order to produce background pattern effects,

a patterned mask such for example as a fine wire mesh or other foraminated material may be interposed between the incident electron beam and the material upon which the production or reproduction is to be made.

Alternatively a patterned metal mask of gOOd heat conductivity may, for this purpose, be introduced immediately behind, and in contact with, the material on which the production or I'BDIOT duction is to be made.

The making of heteroohromatic reproductions of a coloured object or scene on transparent material, for example colour cinematograph films, may also be carried out by the method according to the invention.

To produce a single cinematograph film of stationary or moving objects in natural colours, at least three coloured component reproductions may be made on a transparent strip in register with one another in the manner described above with reference to Figure 3. It is not possible to proceed by scanning and transferring elemental parts of the three coloured compositions simultaneously, since it is necessary to take account of the inevitable time lag which must exist due to the need for the film to travel from the field of one modulated electron beam to the field of the next.

The formation of the three coloured component reproductions in correct register with one another may be accomplished by employing means providing a delay or time lag, introduced between the second and third inconoscopes I I and H and the corresponding cathode ray tube l3 to which they are connected. By this means the picture signals necessary for modulating the first electron beam scanning the yellow composition are transmitted, immediately after inversion and amplification, to modulate the first electron beam it, those required for modulating the second electron beam scanning the red composition are delayed until the yellow component reproduction formed previously reaches the correct position with respect to the second electron beam, and those necessary for modulating the third electron beam scanning the blue composition are delayedstill further until the combined yellow and red component-reproductions have reached the correct position with respect to the third electron beam, so that the blue component reproduction is formed in register with the previously formed yellow and red component reproductions.

Alternatively in the production of such a coloured film, two of the component reproductions may be made simultaneously and in register on opposite sides of the film, e. g. by the method described with reference to Figure 5, and the third component reproduction formed subsequently but in correct register with the two component reproductions previously formed, a suitable delay or time lag circuit or mechanism being interposed between the third iconoscope and therespective electron beam so that the third component reproduction is formed in correct register with the other two.

Again, in the formation of a heterochromatic reproduction of a stationary or moving coloured objecton a film suitable for cinematograph projection, the component reproductions may be made simultaneously upon three separate thin transparent strips and the three strips subsequently brought together so that the simultaneously formed components are in register with one another. Alternatively two films may be employed, two colour component pictures being formed by transference 'of compositions to the two sides of one of the films simultaneously and in register and the third coloured component formed simultaneously by the transference of A another composition upon the other film, the two films being subsequently brought together so that the three corresponding component reproductions are in correct register with one another. Since all colour components of a single picture are in this case formed simultaneously, the provision of a delay or time lag is unnecessary.

The transparent strip materials upon which the coloured component reproductions are formed may. be combined permanently to form a single coloured .film'by sealing the strips together along their longitudinal edges.

It will be understood that in some cases the time required for bringing about the softening and transference of the transfer compositions may be such as to make it desirable to scan with the modulated electron beam at speeds lower than the scanning speeds normally employed in general television practice. For this purpose the picture signals generated by the iconoscopes may be recorded, usually optically and in known manner, and the optical records may be made use of subsequently, for the purpose of regenerating, at a speed lower than that at which they were recorded, the required picture signals for modulating the electron beam. The rate of linescanning of the electron beam and also the rate of frame-scanning thereof, or the rate of movement of the strip material, as the case may be, are of course correspondingly reduced.

It will be understood that the pick-up tube or iconoscope may be connected either directly, or through a radio link with one or more corresponding printing units, and the productions or reproductions may be made either close to, or at one or a number of situations remote from the object or scene to be reproduced.

In some cases it is an advantage to preheat the layer of composition on the composition coated band or bands, to a temperature in the region of, but a little below, the softening point of the composition, in order to reduce the amount of additional heat which is required to be generated by the bombardment of the composition by the beam of radiant or corpuscular energy for softening the composition sumcient to render it transferable. This preheating may be carried out in many ways. For example the composition may be scanned with an unmodulated electron beam (i. e. an electron beam of constant intensity) just before the composition is scanned by the modulated electron beam, or in cases where a composition-coated band is introduced into the highly evacuated chamber through a liquid seal, such preheating may be carried out by maintaining the liquid in the seal at the required temperature. Any other convenient means of preheating, if necessary thermo-statically controlled, may however be used. Since only a slight rise in temperature will then be required to render the transfer compositions transferable, the speed :2

of scanning of the electron beam in the printing unit may be higher.

The printing unit may include means whereby the electron beam may be caused to sweep out a visual picture, for example by causing the fluorescence of a suitably disposed fluorescent screen, visible from the exterior of the apparatus. This visual picture may be utilised as an aid to the accurate setting-up and adjustment of the apparatus before reproduction by the method a.

according to the invention.

Further, making use of the method according to the invention, a material, containing, consisting of or coated with a substance or composition which is capable of being softened at least once by the application of heat and which has a re-- quired degree of solving power or tackiness when in that condition, is arranged to contact a further material containing or coated with a col oured component, such for example as an undissolved dye or a pigment dispersion loosely held in a carrier so that it is capable of being transferred to those parts of the substance or composition which have been rendered dissolving or tacky under the influence of heat generated by the controlled radiant energy or corpuscular beam which scans the surface of the first mentioned material.

The first mentioned material may have a coating of for example a thermoplastic resinous acid such as abietic acid or a solid fatty acid having the required softening point, or a thermoplastic mixture containing wax and a fatty acid, and the second mentioned material may be provided with a coating of an undissolved basic dye dispersion held in casein. In this example a production or reproduction is made on the first mentioned material by transference of dye thereto. Alternatively the second mentioned material may be coated either with a mixture of an undissolved basic dye and a white pigment held in casein or it may have a coating of an undissolved basic dye dispersion in casein masked with a thin layer of a white pigment, and the production or reproduction made either on the first mentioned material having an acidic constituent, or on the second mentioned material, or upon both simultaneously.

A thin preliminary coating of a resinous, waxy or like substance or composition, tinted or coloured if desired may be provided on the surface of the material or body upon which a production or reproduction is to be made. This coating improves the affinity of the surface of the material for the heat-softenable substance or composition which is to be transferred thereto and may, if desired, contain a substance capable of reacting With the transferred substance or with a constituent of the transferred composition. For example a mordant capable of reacting with a dye constituent of a coloured composition may be incorporated in the resinous or waxy layer.

In such cases preheating may be carried out, and the material on which a production or reproduction is to be made, provided with such a thin preliminary coating of a resinous, waxy or like substance or composition, may be separately scanned, prior to coming into contact with the material bearing the heat-softened substance or composition, with a separate unmodulated electron beam to render the resinous or waxy coating soft or tacky, in which condition it assists transference of the softened parts of the heat-softened substance or composition to be transferred.

Alternatively such preliminarily coated material on which the production or reproduction is to be made may be separately scanned with a further electron beam which is also modulated by the picture signals derived from the scanning device, in phase with and to produce the same amplitude of modulation and width of scan as, the electron beam scanning the surface bearing the heat-softenable and transferable substance or composition. In this case the preliminary resinous or waxy coating is softened only at parts which correspond to and come subsequently into contact with those parts of the transferable substance or composition which are being softened for transference.

Again, the surface bearing the transferable substance or composition may be scanned by an unmodulated beam to render the transferable substance or composition soft, and the surface of the material bearing the resinous or waxy coating may be scanned by the modulated beam so that when the two surfaces come subsequently into contact, parts of the softened transferable substance or composition are transferred in correspondence with those parts of the resinous or waxy coating which have been softened.

The transfer methods herein described may be used for the making of etch resists on a wide variety of materials, such for example as metals and glass, and such resists may be used e. g. in the making of decorative effects, or for the making of printing plates or other image-carrying forms, which may be used for printing purposes in conjunction with known printing processes.

For example, an offset plate may be produced directly by the transference of an etch resistant composition, such for example, as stearic acid or palmitic acid to build up the etch ground (fat picture) on for example a zinc sheet.

Alternatively an ordinary letter-press block may be produced by transferring elements of an acid resistant thermoplastic composition to form an etch ground on a plate which can then be subjected to the action of an etch bath in the usual manner.

As a further alternative a transfer paper may be produced by the method according to the present invention and the required printing plate may be produced using this transfer paper in a manner well known in the printing art.

Etch-resists for use in making patterned stencils, or other patterned or apertured materials such as wire mesh may also be made, the materials bearing such resists being subsequently etched right through to produce the required apertures.

The compositions used for the production of such etch-resists need not of course be coloured.

The present invention may also be utilised for the production of three-dimensional or reiief reproductions of an object, or scene, or other representation. Such reproductions are produced by transferring much larger amounts of composition onto the material on which the reproduction is to be made and this may be accomplished either by increasing the amplification of the picture signals generated by the iconoscope, or by reducing the line-scanning speed of the modulated beam in the printing unit, or by allowing the modulated beam to line-scan the face of the composition more than once, or by carrying out both amplification and multiple line-scanning simultaneously.

When producing such reproductions in relief employing the methods described earlier by reference to Figures 1 to 3, the apparatus may be operated in such a manner that the strip-material, on which the reproductions are to be made, is drawn through the printing unit in successive steps, so that the electron beam can scan a given line the required number of times before the strip-material moves forward step-by-step in synchronism with the frame-scanning taking place in the iconoscope. The electron beam in the iconoscope is of course arranged to scan the corresponding line on the image formed on its mosaic the same number of times before the frame-scan time base of the iconoscope causes the electron beam in the iconoscope to commence scanning the next following line on the image on its mosaic. As before the line-scan time base of the iconoscope is electrically synchronised with that of the cathode ray tube in the printing unit.

Productions or reproductions in relief made by the transfer of a resinous thermoplastic substance or composition, subsequently hardened if necessary, may be used directly as a printing surface for subsequent use, or as a guide in the production of electros. Alternatively such hardened reliefs may be used as matrices, or as punches in the productions of matrices. It will be understood that a matrix may also be produced directly on material by abstraction of the transferable substance or composition from the material.

Make-ready consisting of a suitably shaped relief for use in conjunction with e. g. printing plates or blocks in known printing processes may also be made by the methods according to the invention. For example a. relief, varying in height according to the tone value of a printing plate can be produced by transferring a resinous compound to thin sheet material. The transferred resinous relief, subsequently hardened, if necessary, forms a make-ready which may be used in the usual manner, e. g. as an underlay or an overlay.

The present invention may also be utilised in the production of hectographic printing sheets by forming a reproduction of mirror script and other laterally inverted representations, symbols or pictures using a transfer composition consisting of an undissolved dye, soluble in a particular group of solvents, dispersed in a medium substantially insoluble in that solvent group For example an alcohol-soluble dye may be used and the resulting hectographic printing sheet used in conjunction with a duplicating machine of the spirit-soluble kind.

Patterned silk screens, for use in the known silk-screen printing processes, may also be produced utilising the present invention. For example, a plain, i. e. unpatterned silk screen may be dipped in a thermoplastic material, such for example as wax, which forms a thin coating on the screen The coated screen is then placed in contact with an absorbent material which will absorb the thermoplastic material when in the molten state, and then exposed to the action of a scanning electron beam, modulated by signals generated from an iconoscope, with the absorbent material behind the coated screen, i. e. on the opposite side to that of the source of the electron beam. The heat generated by the modulated scanning electron beam causes some of the composition to melt and this melted composition is absorbed by the absorbent material. The result is a patterned silk screen.

Patterned silk screens may also be made according to the invention by transferring composition to an uncoated screen or mesh to form a production 0r reproduction thereon; the transferred composition closing the appropriate apertures of the mesh to prevent the flow of ink therethrough when the silk screen is used.

I claim:

1. Apparatus for producing images including an evacuated chamber, means for forming and controlling an electron beam within said chamber, two strips one of which is treated with a heat-softenable material, and means for introducing said strips into and withdrawing said strips from said chamber, said means comprising a liquid sealing column, located between the atmosphere and said chamber and guide members by means of which said strips are moved through said column and through said chamber.

2. Apparatus for producing images including an evacuated chamber, means for forming and controlling an electron beam within said chamber, two strips one of Which is treated with a hea't-softenable material, and means for introducing said strips into and withdrawing said strips from said chamber, said means comprising a first liquid sealing column in communication with the interior of said chamber and a set of guide members by means of which the treated strip is moved through said first column and through the interior of said chamber, a second liquid sealing column in communication with said chamber, a mechanical seal located between said second column and the atmosphere and a further set of guide members by means of which the other of said strips is moved through said mechanical seal, through said second column and through the interior of said chamber.

3. Apparatus for producing images, said apparatus including an evacuated chamber; two

surfaces, one of which contains a material which can be softened at least once by the action of heat; means for bringing said surfaces into contact with each other within said chamber; a source of radiant energy; means for directing a beam from said source toward said surfaces; means for controlling the intensity of said beam; and means for causing said beam to scan said heat-softenable material to soften predetermined parts thereof, whereby matter is transferred from a selected area of one of said surfaces to an equivalent area of the other, in correspondence with said softened parts of said material, when the two surfaces are in contact.

4. Apparatus for producing images, said apparatus including an evacuated chamber; two surfaces, one of which contains a material which can be softened at least once by the action of heat; means for bringing said surfaces into contact with each other within said chamber; means for forming and controlling a beam of radiant energy; means for directing said beam toward said surfaces; and means for causing said beam to scan said heat-softenable material to soften predetermined parts thereof whereby matter is transferred from a selected area of one of said surfaces to an equivalent area of the other, in correspondence with said softened parts of said material, when the two surfaces are in contact.

5. Apparatus for producing images, said apparatus including an evacuated chamber; two surfaces, one of which contains a material which can be softened at least once by the action of heat; means for bringing said surfaces into contact with each other within said chamber; means for forming an electron beam Within said chamber; means for controlling the intensity of said electron beam; and means for causing said electron beam to scan said heat-softenable material to soften predetermined parts thereof, whereby material is transferred from a selected area of the surface containing said material to an equivalent area of said other surface, so as to form the required image thereon.

6. Apparatus for making reproductions of objects, said apparatus including an evacuated chamber; two surfaces, one of which contains a material which can be softened at least once by the action of heat; means for bringing said surfaces into contact with each other within said chamber; means for forming an electron beam within said chamber; means for controlling the intensity of said electron beam by modulating said beam with picture signals representative of the object to be reproduced; and means for causing the modulated electron beam to scan said heat-softenable material to soften predetermined parts thereof, whereby material is transferred from a selected area of the surface containing said material to an equivalent area of said other surface, so as to form the required image thereon.

7. Apparatus for making reproductions of objects, said apparatus including an evacuated chamber; a surface bearing a material which can be softened at least once by the action of heat; a second surface; means for forming an electron beam within said chamber; means for controlling the intensity of said electron beam by modulating said beam with picture signals representative of the object to be reproduced; means for causing the modulated electron beam to scan the heat-softenable material to soften predetermined parts thereof; and means for bringing said two surfaces into contact with each other before the softened parts have hardened, whereby said softened parts of said heat-softenable material are transferred from a selected area of the surface bearing said material to an equivalent area of said other surface, so as to form the required reproduction thereon.

8. Apparatus for making visible images on a transparent base-material, said apparatus including an evacuated chamber; a surface within said chamber, said surface bearing a coating of a heat-softenable material; a transparent basematerial; means for forming an electron beam within said chamber; means for controlling the intensity of said electron beam by modulating said beam with picture signals representative of the object to be reproduced; means for causing the modulated electron beam to scan the heat-softenable material to soften predetermined parts thereof; and means for bringing said surface into con tact with said transparent base-material, whereby the softened parts of said heat-softenable material are transferred from a selected area of said surface to an equivalent area of the transparent base-material, whilst remaining adherent to said surface, so that an image is formed which can be viewed through said transparent base-material and which can be destroyed by parting said surface and said base-material; and means for destroying said image at will.

9. Apparatus for making images on a transparent base-material, said apparatus including an evacuated chamber; a surface within said chamber, said surface bearing a coating of a heat-softenable material; a transparent basematerial; a source of radiant energy; means for directing a beam from said source toward said surface; means for controlling the intensity of said beam; means for causing said beam to scan said heat-softenable material to soften predetermined parts thereof; and means for bringing said surface into contact with said transparent base material whereby the softened parts of said heat-softenable material are transferred from a selected area of said surface to an equivalent area of the transparent base material whilst remaining adherent to said surface, so that an image is formed which can be viewed through said transparent base material and which can be destroyed by parting said surface and said bas material; and means for destroying said image at will.

10. Apparatus for making images, said apparatus including an evacuated chamber; a strip on which the images are to be formed; a flexible band bearing a coating of a material which can be softened at least once by the action of heat; means for bringing said strip and said band into pressure contact with each other within said chamber; means for forming an electron beam wi hin said chamber; means for controlling the intensity of said electron beam by modulating said beam with picture signals representative of the image to be formed; means for causing the modulated electron beam to lineand frame-scan the surface of said heat-softenable material in synchronism and the corresponding lineand frame-scannin of the object, to soften predetermined parts of said material: and means for bringing said stri and said flexible band into contact w th each other before said softened parts have hardened, whereby said softened parts of said heat-softenable material are transferred from a selected area of said flexible band to an equivalent area of said strip.

11. Apparatus as claimed in claim 10, wherein 23 said flexible band is provided with a cellular surface, said surface containing a plurality of relatively small isolated masses of the heat-softenable material in the cells thereof.

12. Apparatus for making images, said apparatus including an evacuated chamber; a strip on which the images are to be formed; a flexible band bearing a coating of a material which can be softened at least once by the action of heat; means for bringing said strip and said band into pressure contact with each other within said chamber; means for forming an electron beam within said chamber; means for controlling the intensity of said electron beam by modulating said beam with picture signals representative of the image to be formed; means for causing the modulated electron beam to line-scan the surface of the heat-softenable material in synchronism with the corresponding line-scanning of the object, to soften predetermined parts of said material; means for moving said strip and said flexible band through said chamber at a speed related to the frame-scanning of the object; and means for bringing said strip and said flexible band into contact with each other before said softened parts have hardened, whereby said softened parts of said material are transferred from a selected area of said flexible band to an equivalent area of said strip.

13. Apparatus as claimed in claim 12, wherein said flexible band is provided with a cellular surface, said surface containing a plurality of relatively small isolated masses of the heat-softenable material.

14. Apparatus for making images, said apparatus including an evacuated chamber; a strip on which the images are to be formed; a flexible band bearing a coating of a material which can be softened at least once by the action of heat; means for bringing an area of said strip into surface contact with a predetermined area of said flexible band within said chamber; means for holding said strip and said band stationary and in mutual contact whilst in said chamber; means for forming an electron beam within said chamber; means for controlling the intensity of said electron beam by modulating said beam with picture signals representative of the image to be formed; means for causing the modulated beam to scan said heat-softenable material in synchronism with the corresponding scanning of the object to soften predetermined parts of said heatsoftenable material, whereby said softened parts of said material are transferred from said flexible band to said strip; and means for moving said strip and said band to bring a fresh area of said strip into contact with a corresponding fresh area of said flexible band.

15. Apparatus as claimed in claim 14, wherein said flexible band is provided with a cellular surface, said surface containing a plurality of relatively small isolated masses of the heat-softenable material.

16. Apparatus for producing images, said apparatus including an evacuated chamber; two surfaces, one of which contains a material which can be softened at least once by the action of heat; means for bringing said surfaces into contact with each other within said chamber; a source of radiant energy; means for directing a beam from said source toward said surfaces; means for controlling the intensity of said beam; means for preheating the heat-softenable material to a temperature in the region of, but below the softening temperature thereof; and means for causing said beam to scan said heat-softenable material so as to soften predetermined parts thereof, whereby matter is transferred from a selected area of one of said surfaces to an equivalent area of the other surface in correspondence with said softened parts of said material, when the two surfaces are in contact.

17. Apparatus for producing images, said apparatus including an evacuated chamber; two surfaces, one of which contains a material Which can be softened at least once by the action of heat; means for bringing said surfaces into contact witheach other within said chamber; means for forming an electron beam within said chamber; means for controlling the intensity of said electron beam; means for preheating the heat-softenable material to a temperature in the region of, but below, the softening temperature thereof; and means for causing said electron beam to scan said heat-softenable material, so as to soften predetermined parts thereof, whereby material is transferred from a selected area of the surface containing said material toan equivalent area of said other surface, so as to form the required image thereon.

18. Apparatus for producing images, said apparatus including an evacuated chamber; two surfaces, one of which contains a material which can be softened at least once by the action of heat; means for bringing said surfaces into contact with each other within said chamber; means for forming an electron beam within said chamber; means for controlling the intensity of said electron beam; means for forming a further and discrete electron beam within said chamber; means for causing said further electron beam to scan the surface of said heat-softenable material, so as to preheat said material to a temperature in the region of, but below, the softening temperature thereof; and means for causing the first-mentioned electron beam to scan said heat-softenable material, so as to soften predetermined parts thereof, whereby material is transferred from a selected area of the surface containing said material to an equivalent area of said other surface, so as to form the required image thereon.

, 19. Apparatus for making images, said apparatus including an evacuated chamber; two surfaces, one of which is provided with a coating of a heat-sensitive material which is rendered tacky under the influence of heat and the other of which contains a material which can be rendered soft and transferable, at least once, by the action of heat; means for bringing said surfaces into contact with each other within said chamber; means for forming two discrete electron beams within said chamber; means for identically controlling the intensities of each of said electron beams; and means for causing said beam to separately scan the surfaces of the heatsensitive material and the heat-softenable material, so as to render predetermined parts of the heat-sensitive material tacky, and so as to soften corresponding parts of the heat-softenable material, whereby said softened parts are transferred from one surface to the other surface, when said surfaces are in contact.

20. In apparatus for making images, an evacuated chamber; means for forming and controlling an electron beam within said chamber; two surfaces within said chamber; means for bringing said two surfaces into contact with each other within said chamber; means for introducing said surfaces into and withdrawing said surfaces from 25 said chamber, said last means comprising a liquid sealing column located between the atmosphere and said chamber; and guide means for movin said surfaces through said column.

21. In apparatus for making images, an evacuated chamber; means for forming and controlling an electron beam within said chamber; two surfaces, one of which is treated with a material which can be softened at least once by the action of heat; means for bringing said surfaces into contact with each other within said chamber; means for introducing said surfaces into and withdrawing said surfaces from said chamber, said last means comprising a liquid sealing column located between the atmosphere and said chamber; and guide means for moving said surfaces through said column and through said chamber.

22. Apparatus for making reproductions of objects, said apparatus including an evacuated chamber; a first body; a second body provided with a heat-softenable material on at least one of the surfaces thereof; means for bringing said bodies into contact with each other within said chamber, with a surface of said first body facing that surface of said second body which bears the heat-sof tenable material; a source of modulated radiant energy of sufficient intensity to soften said material; means for forming a beam of said radiant energy; means for directing said beam to- Ward said bodies; and means for causing said beam to scan the heat-softenable material, so as to soften parts thereof, whereby matter is transferred from a selected area of one of said surfaces to an equivalent area of the other surface, in

correspondence with said softened parts of said material, when the two surfaces are in contact.

23. Apparatus for making reproductions of objects, said apparatus including an evacuated chamber; a first body; a second body provided with a heat-softenable material on at least one of the surfaces thereof; means for bringing said bodies into contact with each other Within said chamber, with a surface of said first body facing that surface of said second body which bears the heat-softenable material; a source of corpuscular energy; means for forming a beam of said corpuscular energy; means for controlling the intensity of said corpuscular beam by modulating said beam with picture signals representa- 3 tive of the object to be reproduced; and means for causing the modulated beam to scan the heat-softenable material, so as to soften predetermined parts thereof, whereby matter is transferred from a selected area of one of said surfaces to an equivalent area of the other surface, in correspondence with said softened parts of said material, when the two surfaces are in contact.

24. Apparatus as claimed in claim 23, wherein said beam of corpuscular energy is an electron beam.

25. Apparatus for making reproductions of objects, said apparatus including an evacuated chamber; a strip on which the required reproductions are to be made; a plurality of flexible bands treated respectively with a plurality of materials which can be softened at least once by the action of heat; means for forming an equal plurality of discrete electron beams within said chamber; means for controlling the respective intensities of said discrete beams by modulating each of said beams with picture signals representative of said objects; means for causing each of said plurality of beams respectively to scan a different one of said plurality of heat-softenable materials, so as to soften predetermined parts thereof; and means for successively bringing said plurality of flexible bands into contact with the strip within said chamber, whereby the softened parts of said materials are transferred successively from the corersponding flexible bands to said strip so as to form the required reproductions thereon.

26. Apparatus for producing images, said apparatus including a chamber; means for evacuating said chamber, and for maintaining the vacuum therein; two surfaces, one of Which is treated with a material which can be softened at least once by the action of heat; means for bringing said surfaces into contact with each other within said chamber; an electron gun positioned within said chamber for forming an electron beam; means for controlling the intensity of said beam; and means for causing said beam to scan the heat-softenable material, so as to soften parts thereof, whereby the softened parts are transferred to the surface on which the object reproductions are to be formed, when said two surfaces are in contact.

JOSEF GROAK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,724,572 Geisen Aug. 13, 1929 1,819,264 Ranger Aug. 18, 1931 2,109,109 Finch -1 Feb. 22, 1938 2,227,109 Shankweiler Dec. 31, 1940 2,291,476 Kernkamp July 23, 1942 2,301,024 DHumy Nov. 3, 1942 2,309,506 Herbst Jan. 26, 1943 2,354,263 Hillier July 25, 1944 

